Continuous casting machine

ABSTRACT

In a continuous casting machine, having a mold and means for withdrawing and guiding a casting emerging and lowered from the mold, a pair of endless belts or chains carrying plates and disposed on opposite sides of and along and urged against the casting for the plates to engage the casting, the belts running in synchronism with the lowered casting; the plates having relief profile to engage the casting with less than the entire surface area of a plate, preferably with about 10 to 30 percent thereof, there being protrusions and indentations for a coolant to flow around the protrusions in contact with the casting.

United States Patent Petersen 51 Oct. 24, 1972 [54] CONTINUOUS CASTINGMACHINE 3,283,368 11/1966 Homan ..l64/283 X L 3 468 362 9/1969 Burkhardtet al 164/283 X 72 l t Ulrich P te D l rf- 1 men Lohausen 3,625,49812/1971 Adamec et al ..l64/283 3,446,270 5/1969 Michelson ..164/282 [73]Assignee: Maanesmann Aktiengesellschaft,

Dusseldorf, Germany Primary Examiner-J. Spencer Overholser AssistantExaminer-V. K. Rising [22] Filed. Sept 1971 AttorneyRalf H. Siegemund etal. [21] Appl. No.: 179,957

[ ABSTRACT [30] Foreign Application Priority Data In a continuouscasting machine, having a mold and means for withdrawing and guiding acasting emerging Sept 1970 Germany 20 46 6459 and lowered from the mold,a pair of endless belts or chains carrying plates and disposed onopposite sides (g1. ..164/282, of and along and urged against thecasting for the plates to engage the casting the belts running in [58]Field of Search ..l64/282, 283, 278 US, 89 Synchronism with the loweredcasting; the Plates ing relief profile to engage the casting with lessthan [56] References cued the entire surface area of a plate, preferablywith UNITED STATES PATENTS about 10 to 30 percent thereof, there beingprotrusions and indentations for a coolant to flow around the gavlsprotrusions in contact with the casting. agg 3,167,830 2/1965 Hazelettet al 164/283 X 10 Claims, 7 Drawing Figures PATENTEuucm me 0 I saw 1 or2 E E ii- E E -l- E E E E E E E -L -L E E E e m? m/ M A CONTINUOUSCASTING MACHINE The present invention relates to improvements incontinuous casting machines, particularly as to guiding and supporting acontinuously cast ingot, using plates mounted on an endless belt.

Endless belts or chains have been used for supporting a casting uponwithdrawal'from the mold. Herein plates or plate-like chain elementshave smooth surface that engage the casting. However, the castingrequiresalso cooling, and it was found otherwise that direct cooling ismuch more effective than indirect cooling, at least right below themold. Covering the casting by means of such plates reduces, therefor,cooling in the zones to what is now secondary cooling. This disadvantageis particularly noticeable for a high production rate and highwithdrawal speed of the casting as lowered from the mold.

The usually employed rolls or stationary plates are also no longerusable in high speed machines. As the skin of the casting is quite thinat one location or another the thinner, the higher the withdrawal speedthe skin will bulge'between two rolls and isno longer adequatelysupported. The providing of stationary support plates directlyunderneath the mold does not solve that problem, as sliding friction isexerted to a significant extent upon the skin, which may easily rupture.Also, these plates wear out quite fast.

It is an object of the present invention to avoid these difficulties anddisadvantages and to provide for support of a casting that is withdrawnfrom the mold at a high speed, without detriment to cooling.

It is another object of the invention to improve endless chain or beltconstruction to be used for supporting a withdrawn ingot. These belts orchains are to have plates that are urged towards the casting fromopposite sides and run therewith at casting withdrawal speed. It is aparticular feature of the present invention that the plates have reliefprofile to engage the casting with less than the entire surface of aplate as facing the casting. The protrusions, elevations, projectionsetc. that engage the casting and establish the relief areto cover notmore than 50 percent, of the plate surface; preferably they cover onlyto 30 percent.

The type of protrusions that form the relief may differ. It was found ofadvantage to use dot-like or circular-like protrusions. Annularprotrusions should have diameter of about 10 to 40 mm. Alternatively,the protrusion may set up a line pattern, the lines having width ofabout 10 to 40 mm. Still alternatively, the protrusions may constitute agrid or lattice structure disposed on or being part of a perforatedbase. The lattice type protrusions may be rhombic, rectangular or,preferably, they may be constituted by a network of annular bosses. Theplates are arranged on an endless belt or chain or chains driven bypulleys as is known per se.

Water for cooling is sprayed in between the plates, laterally therefromand through perforations in the plates, whereby the cooling water isdistributed in the channels formed around or along the protrusionsbetween the corresponding indentations of the plate and the adjacentcasting skin.

While the specification concludes with claims particularly pointing outand distinctly claiming the subject matter which is regarded as theinvention, it is believed that the invention, the objects and featuresof the invention and further objects, features and advantages thereofwill be better understood from the following description taken inconnection with the accompanying drawings in which:

FIG. 1 is a side elevation with section through the casting and mold andshowing additionally the novel withdrawal arrangement in accordance withthe preferred embodiment of the invention; and

FIGS. 2, 3, 5 and 6 show side views of plates with different surfacerelief profile;

FIGS. 2a and 4 being respectivelysections through lines 2a2a and 4-4inFIGS. 2 and 3.

Proceeding now to the detailed description of the drawing, in FIG. 1 isshown a mold 1 for continuous casting. Liquid metal is poured'into themold and a casting 2 is lowered and withdrawn from below. The castinghas a solidified skin 2' whichis quite thin immediately below the mold,mostof' the interior of the casting being occupied by a downwardextension of the liquidous pool 2" in the mold. The skin 2' grows withdistance from the mold.

Immediately upon leaving the mold, the casting is engaged and supportedby plates 4 These plates are disposed on endless-belts 3 and 3a. Belt 3runsaround pulleys S and 5, belt 3a runs around pulleys 5a and 5 'a. Atleast, the two lower pulleysS' and Sa are driven, so that the endlessbelts run in synchronism with the lowering speed of the casting.

Farther down along the withdrawal path for the casting there will beprovided the usual withdrawing rolls (not shown) which are driven andwhich provide the necessary.,torque and power for casting withdrawal. Asthat withdrawal drive determines the withdrawing speed, the belt driveswill be synchronized to the withdrawing drive so that the belts move atthe lowering speed of the casting. The belts are tensioned and guided byidler pulleys and by rolls 7 mounted on a support frame 8. Rolls 7provide a particular force for urging plates 4 against the casting.Below the belts, it is presumed that the skin 2' has attainedsufficientthickness so that regular rolls such as 6 suffice to supportthe casting.

As schematically indicated at 9, water is sprayed from the interior ofthe belt system, the coolant being fed laterally thereto. The water issprayed onto the belts from the respective rear to pass throughperforations therein as well as through perforations in the plates 4 andin between adjacent plates The belts are arranged in pairs, one pairbeing shown to engage opposite sides of a slab ingot. The two sidestransverse thereto may be engaged and supported by a similar pair ofbelts with plates.

Proceeding now to FIGS. 2 to 6, various configurations for the platessurfaces will be described. In FIGS. 2 and 2a a plate is shown with aplate base it) proper having protrusions 11 in form of ridges, arrangedin a herring-bone pattern, the inclination being in direction of casting(arrow A). The space between the protrusions form cooling channels sothat water sprayed transversely to the plane of the drawing runs readilyinto these channels from above and down along the casting. It is alsofor this reason that the ridges should not be wider than about 40 mm, tominimize the local areas of indirect cooling.

In FIGS. 3 and 4, the plate is established by a frame 15 and bars 12 toprovide a lattice or grid structure and configuration, leavingperforations 14, through which water is sprayed from behind. Circularbosses 13 are provided on the bars 12, for engagement with the casting.The bosses are quite large in number, so that there is a dense networkof support points for the casting over the entire plate surface, butminimizing areas of contiguous contact.

The plate of FIG. 5 is somewhat simplified; the plate 19 is flat and isprovided with perforations 24, the remaining sections 18 between theperforations establish the profile.

FIG. 6 shows a plate that has also a frame 21 with cross bars or struts12 leaving perforations 23. The frame as well as the cross bars carryprotrusions 25. These protrusions are circular, preferably annular, eachhaving a central opening 26. Spray water may, thus, pass through theperforations 23 as well as through openings 26.

It can, thus, be seen that in each case, with the providing of pluralplates on the endless belts, the casting is supported over a very largearea, by a multitude of densely placed but small support elements. Asthe plates are mounted on the belts with little space between them,there are no large unsupported areas of the casting as is the case uponusing rolls. As the plates run with the casting, little or no frictionoccurs between them, and the channels between the protrusions permitready cooling. The belts themselves should be perforated to permit readypassage of cooling water, or there could be plural, narrow width beltsor chains, permitting water to be sprayed against the rear of plates 4in between the belts or chain elements.

The invention is not limited to the embodiments described above but allchanges and modifications thereof not constituting departures from thespirit and scope of the invention are intended to be included.

lclaim:

1. In a continuous casting machine, having a mold and means forwithdrawing and guiding a casting emerging and lowered from the mold,the improvement 4 comprising:

a pair of endless belts or chains below the mold and carrying plates anddisposed on opposite sides of and along the casting for the plates toengage the casting, the belts running in synchronism with the lowercasting as the casting is lowered;

the plates where engaging the casting having relief profile to engagethe casting with less than the entire surface area of a plate facing thecasting, there being protrusions and indentations in the plates todefine the relief profile;

means for providing coolant to the casting to flow around theprotrusions in contact with the casting; and

means for urging the plates into contact with the casting.

2. The improvement as in claim 1, the protrusions of a plate coveringless than about 50 percent of the surface of a plate as facing acasting.

3. The improvement as in claim 2, the protrusions covering about 10 to30 percent of said plate surface.

4. The improvement as in claim 1, the protrusions being a multitude ofindividual bosses, there being perforations in the plate for passage ofcoolant.

5. The improvement as in claim 1, the protrusion havin circular confiuration.

6. The improveme nt as in claim 5, the protrusions having annularconfiguration with a central opening for passage of coolant.

7. The improvement as in claim 5, the plate having perforations betweenthe protrusions for passage of coolant.

8. The improvement as in claim 1, the protrusions being ridges disposedat an angle to the direction of casting to permit flow of coolant therealong.

9. The improvement as in claim 8, the ridges being about 10 to 40 mmwide.

10. The improvement as in claim 1, the plate having grid-likeconfiguration.

1. In a continuous casting machine, having a mold and means forwithdrawing and guiding a casting emerging and lowered from the mold,the improvement comprising: a pair of endless belts or chains below themold and carrying plates and disposed on opposite sides of and along thecasting for the plates to engage the casting, the belts running insynchronism with the lower casting as the casting is lowered; the plateswhere engaging the casting having relief profile to engage the castingwith less than the entire surface area of a plate facing the casting,there being protrusions and indentations in the plates to define therelief profile; means for providing coolant to the casting to flowaround the protrusions in contact with the casting; and means for urgingthe plates into contact with the casting.
 2. The improvement as in claim1, the protrusions of a plate covering less than about 50 percent of thesurface of a plate as facing a casting.
 3. The improvement as in claim2, the protrusions covering about 10 to 30 percent of said platesurface.
 4. The improvement as in claim 1, the protrusions being amultitude of individual bosses, there being perforations in the platefor passage of coolant.
 5. The improvement as in claim 1, the protrusionhaving circular configuration.
 6. The improvement as in claim 5, theprotrusions having annular configuration with a central opening forpassage of coolant.
 7. The improvement as in claim 5, the plate havingperforations between the protrusions for passage of coolant.
 8. Theimprovement as in claim 1, the protrusions being ridges disposed at anangle to the direction of casting to permit flow of coolant there along.9. The improvement as in claim 8, the ridges being about 10 to 40 mmwide.
 10. The improvement as in claim 1, the plate having grid-likeconfiguration.